Luminous indicating article



July 24, 1956 M. FERRIER 2,756,344

LUMINOUS INDICATING {XRTICLE Filed May 14, 1951 I 2 33 J yluvsmoa MAURICE FERRIE'R United States Patent LUMiNoUs INDICATING ARTICLE Maurice Ferrier, La Chanx-de-Fonds, Switzerland, as-

signor to Bulova Watch Company Inc., New York, Succursale de Bienne, Bienne, Switzerland, a joint-stock company Application May 14, 1951, Serial No. 226,196

Claims priority, application Switzerland May 19, 1950 4 Claims. (Cl. 250-72) This invention relates to luminous articles and methods of making the same, and more particularly to the equipment or ornamentation with luminous material, of a great variety of articles such as clocks, watches, control and measuring instruments, dials and hands, and plates, stands, frames and similar articles.

Articles rendered luminous in whole or in part by the application thereon of luminous materialheretofore have involved certain serious drawbacks. Thus signs, marks, numbers, etc., made or covered with luminous material have suffered from badly defined contours. The luminous material deteriorates rapidly, it becomes dirty and cannot be cleaned or polished without being damaged so it no longer gives the desired result. Moreover, particularly in hot climates, the luminous material is subject to decomposition caused by exposure to sunlight and resulting, in turn, in a blackening of the luminous material. Another important disadvantage of the prior art methods and articles resided in the necessity of admixing to the luminous material a binder whereby to apply it to the article, with consequent loss in luminosity.

The present invention contemplates protecting the luminous material which covers parts which shall be rendered visible in the dark, such as for instance the hour numbers, characters or other markings on a timepiece dial or the hands turning above the dial surface, against deterioration and decomposition owing to direct contact with dust-laden air and with the fingers of the user, or by direct exposure to sunlight without however materially weakening the luminosity of the material.

This protection is attained, in accordance with this invention, by the arrangement, above the exposed surface of a layer of luminous material, which may be a loose powder or a coating of luminous paint containing for instance zinc sulfide, of a transparent body which consists of a material which, owing to its light-absorption spectrum, allows the passage through it of the light emitted by the luminous material, while in daylight there is no indication that the dial is in fact luminous.

In the drawing afiixed to this specification and forming part thereof, several embodiments of the invention are illustrated diagrammatically by way of example.

In the drawing,

Fig. 1 shows, in section, one embodiment of the invention wherein the luminous material is provided in a perforation of the article;

Figs. 2 and 3 show, likewise in section, modifications of the embodiment of the invention shown in Fig. 1;

Fig. 4 illustrates, in section, the disposition of the luminous material in a recess made in the article;

Fig. 5 is a modification, also in section, of the embodiment of the invention shown in Fig. 4;

Fig. 6 illustrates, in section, a further embodiment of the invention including a setting for the stone; and

Fig. 7 shows another mode of execution of the embodiment of the invention shown in Fig. 6.

Referring now to the drawing wherein like parts are denoted by identical reference numerals, and first to Fig.

'1, 1 denotes a plate or other strip of material which, for example may be made of metal or some transparent material. For purposes of description let it be assumed that part 1 is a watch dial,'but it might just as well be part of a control or measuring instrument or could be the hand or pointer of some instrument or apparatus intended to give visible indications in the dark. The dial 1 is provided with a perforation 2 which passes entirely through the dial. A stone 3 is mounted in the top portion of the hole 2. The top of the stone is curved so as to project somewhat beyond the top level of the dial 1. Instead of being polished but uncut, the stone might as well be cut with facets so as to play the part of a lens. Luminous material indicated at 4 is disposed in the hole 2 underneath the stone 3 so it is flush with the bottom of the dial 1. The luminous material, for example, may consist of zinc sulfide. The extent to which the stone 3 projects beyond the top surface of the dial 1 may be varied according to requirements, and the top of this stone may be disposed even below the level of the top dial surface if it is desired, for example, to make room for the passage of a watch hand between the dial and the glass of the watch.

The stone 3 may be a natural or an artificial (synthetic) watch jewel or other technical stone product, a molded stone, etc. The stone is preferably colored but it is to be noted that by reason of the radioactivity of the luminous material 4, the light emanating from the luminous material is not influenced by the coloring of the stone 3. Accordingly, stones of any desired color shade, and even black stones may be used so that in daytime, there is no indication that the dial is in fact luminous.

The modification shown in Fig. 2 differs little from the embodiment of the invention illustrated in Fig. 1, except for the fact that the stone 13 is hollowed out in the bottom and the luminous material 14 is provided in the hollow spaced thus created.

In the embodiment of the invention shown in Fig. 3, the stone 33 is mounted in a ring 5 which in turn is set in the perforation 2 of the dial 1. The luminous material 4 is disposed in a manner similar to that shown in Fig. 1.

Instead of piercing or perforating the dial 1 all the way through, it is equally possible to provide recesses either in the top (Fig. 4) or in the bottom (Fig. 5) portions of the dial 1. The latter arrangement, of course, presupposes that the dial is made of transparent material.

In the embodiment of the invention according to Fig. 4, the luminous material is placed on the bottomof the recess 6 which is then covered with the stone 43 which is forced into the opening of the recess 6.

In the case of Fig. 5, the stone 53 is first inserted into the recess 7, and the luminous material 4 is then placed over the stone 53 so as to fill completely the recess 7.

In the embodiment of the invention according to Fig. 6, the stone 63 is set in a setting 8 which itself is mounted in the perforation 2 which extends all the way through the dial 1.

In the embodiment of the invention according to Fig. 7, the stone 73 is set in a mount 9 which has a bottom flange 10 engaging a corresponding cutout portion in the bottom so as to be firmly mounted therein.

The stones or similar transparent bodies employed, according to the invention, to serve as protective and ornamental covers for the luminous material, may be inserted in the apertures, perforations or recesses not only in the manner indicated in the drawing, i. e. by being forced into the apertures, etc., to be retained therein by friction, or by means of linings or settings provided in the apertures, but also in any other known'manner'such'as by theuse of glue or a similar binding agent.

The invention permits employing luminous material in its pure state and without any binder which materially increases its luminosity. For example, in the embodiment of the invention according to Fig. 4, the luminous material 4 being placed on the bottom of the'recess 6 and covered bythe stone 43, may be provided as a powder, yet is firmly held in place. In the other embodiments of the invention, a cover made of metal, for example, may be provided to cover the open side of the hole; this cover may be forced into the hole or else may be mounted on the bottom of thedial. Protective lacquer may also be provided to hold the luminous material in place. 7 I V a I wish it to be understood that I do not desire to be limited to the exact details of construction, design and operation shown and described, as numerous modifications within the scope of the appended claims may occur to a person skilled in the art.

I claim:

1. In an indicator, the combination of a member formed with a depression, a layer of luminous material arranged in said depression and a transparent body covering said layer of luminous material, saidtransparent body having the properties of transmitting light emitted by said luminous material and absorbing light of the wave lengths normally reflected by said luminous material,

whereby the said luminous material in the said indicator is invisible in daylight.

2. The combination of Claim 1 in which the transparent body is a synthetic watch jewel.

3. The combination according to claim 1 in which the transparent body isa colored synthetic watch jewel.

4. In an indicator, the combination of a member formed with a depression, a layer of luminous material arranged in said depression and a'transparent body covering said layer of luminous material, said transparent body having the properties of transmitting light emitted by said luminous material and absorbing light of the wave lengths normally reflected by said luminous material, whereby the said luminous material in the said indicator is visible in the dark and invisible in daylight.

References Cited in the file of this patent V UNITED STATES PATENTS 1,173,110 'Junghans Feb. 22,1916 1,246,080 Frank Nov. 13, 1917 1,388,855 Fordyce Aug. 30, 1921 1,392,604 Smith Get. 4, 1921 1,420,829 Frank June 27, 1922 1,466,286 Hearn Aug. 28, 1923 

1. IN AN INDICATOR, THE COMBINATION OF A MEMBER FORMED WITH A DEPRESSION, A LAYER OF LUMINOUS MATERIAL ARRANGED IN SAID DEPRESSION AND A TRANSPARENT BODY COVERING SAID LAYER OF LUMINOUS MATERIAL, SAID TRANSPARENT BODY HAVING THE PROPERTIES OF TRANSMITTING LIGHT EMITTED BY SAID LUMINOUS MATERIAL AND ABSORBING LIGHT OF THE WAVE LENGTHS NORMALLY REFLECTED BY SAID LUMINOUS MATERIAL, WHEREBY THE SAID LUMINOUS MATERIAL IN THE SAID INDICATOR IS INVISIBLE IN DAYLIGTH. 